Phenylketonuria (PKU) is caused by homozygosity for a recessive allele and can cause a severe form of mental retardation if not detected early. The prevalence of PKU (genotypeÿaa) is 1 per 15,000 newborns in the United States according to the National Institutes of Health (2001).ÿGiven the above data, what is the expected allele frequency of theÿaÿallele? Write your answer using three decimal points and include the first zero. For example, 0.050 or 0.123.ÿDo not write .050 or .123.ÿFailing to follow these instructions will result in no credit for this question, irrespective of correctnes.ÿfreqÿaÿ= [x]